Electric motor



(No Model.)

W. BRADBURY.

ELECTRIC MOTOR.

No. 293,556. Patented Feb. 12, 1884. F191. J a

M w y a 0 M1201 )VALTER BRADBURY, OF ST. LOUIS, MISSOURI, ASSIGXOR TO (,tliOlZGE h.

CALHOUX, OF SAME PLACE.

SPECIFICATION forming part of Letters Patent No. 293,556, dated February 12, 1884:.

(No model.)

To aZZ whom it may concern.-

Be it known that I, WALTER BRADBURY, of the city of St. Louis, in the State of Missouri, have invented a certain new and useful Inr provement in Electric Motors, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part ofthis specification, and in which Figure 1 is a side elevation. Fig. 2 is an end view, part broken away. Fig. 3 is a top view, part in section. Fig. 4 is a section on line t 4., Fig. 3. Fig. 5 is a section on line 5 5, Fig. 4. Fig. 6 is an inside view of one of the magnets, and Fig. 7 is an edge view of the armature.

My invention relates, first, to a means of preventing the armature from stopping on a dead-center when in use, and for starting it when it is stopped near that position, as hereinafter more fully explained; and my invention further relates to agovernor for regulating the armature or bobbin, and by which it can be reversed when desired.

Referring to the drawings, A represents the supporting-base; B, the helices; O, the magnets; D, the armatnre or bobbin; D, the shaft of the armature, having a pulley, D E, the commutator surrounding the shaft, but insulated therefrom; and F F, the main conducting-wires, all of which are of common well known construction, except I provide the armature with ribs or projections and the magnets with corresponding grooves or depressions, and, instead of connecting both of the main conducting-wires to the frame, I connect one thereto and the other to a governor-disk, which connects with the commutator by means of spring-plates similar to those commonly used to form a communication between the frame and the commutator.

The ribs D on the armature, of which there may be any desired number, (I have shown three on each side,) are of a diamond or double-V shapethat is, they are the widest and project the farthest in the center, tapering to a point at each end. (See Figs.

1, 2, 3, and 7.) The grooves G in the inner parts of the magnets, which receive the ribs on the bobbin or armature, are the narrowest at their centers and are V -shaped. (See Figs. 2, 8, and 6.) The effect given by these peculiar-shaped ribs and grooves is that as the ribs enter the grooves the power of attraction constantly increases until the points of the ribs pass the centers of the grooves, and then the power of repulsion is the greatest, gradually decreasing as the ribs leave the grooves,

and the sides of the grooves,thus acting on the I sides of the ribs after the armature has reached the point where the body of the magnets have little or no effect on it, overcomes theliability of the armature stopping at this point, and, should the circuit be broken and the bobbin stopped when it (the bobbin) is in this posi tion, where the magnets cannot operate it, the circuit, through means of the tapering ribs and grooves, will be enabled to start the armature turning.

G represents a metal disk located at one end of the armature, and supported by the shaft of the armature,or in any suitable manner, so as to be turned freely when desired.

H represents two spring-brushes, secured to the disk by means of a bracket, I, (see Figs. 3, 4, and 5,) and whose free ends bear on the commutator, as shown. These springs are very similar to those already in use to form a connection between the frame and the commutator; but, instead of connecting them to the frame, I secure them to the disk, as mentioned. One of these springs is insulated from its bracket, as shown in Fig. .3, and to it one of the coinlucting-wires is secured, see Fig. 3,) and the other conducting-wire is secured to the frame, (see Figs. 1 and 3,) against which the disk bears, or with which it has communication, and as the other springisnotinsulated from the diska communication is had between the frame and commutator. The disk is held from turning by a pawl or detent, J, secured to the frame, and its free end fitting in notches G of the disk. (See Fig. 4.) By raising the pawl out of engagement with the disk the lat tcr can be turned to change the points of bearing of the plates on the commutator relative to the magnets, so that the power given to the armature can be varied or regulated or by 2. In an electric motor, the adjustable disk provided with notches on its periphery, to be r 5 engaged bya pawl secured to the frame, and provided with brushes or plates, whose free ends bear upon the commutator, and one of which is insulated and has connected to it one of the conducting-wires,substantially as shown 20 and described, for the purpose set forth.

VALTER BRADBURY.

In presence of SAML. KNIGHT, Gno. H. KNIGHT. 

